A. Field of the Invention
This invention relates to inspection systems for overwrap on packaged goods to ensure a complete and quality overwrap, proper graphics, and pack construction.
B. Description of the Prior Art
Inspection systems for packaged goods generally are known for use as quality control devices, and process control for manufacturing. Consumers may outright reject or return defectively packaged merchandise, for a variety of reasons. Improperly sealed consumer goods can raise safety and freshness concerns and perfectly good items will routinely be returned for refund and disposal with concomitant losses. Inspection is one way of ensuring a minimum of packaging defects.
High speed inspection systems have limited time to determine the acceptability of a product and are generally limited to examination of planar surface features; e.g. a misprint or a defect in the product exterior. Objects with a circular cross section; e.g. cigarettes, can be scanned sequentially using image scanning technology such as that in U.S. Pat. Nos. 5,235,649, 5,366,096, 5,414,270, 5,013,905, and 4,976,544, which are incorporated herein in their entireties.
However, a transparent or partially transparent wrapper; e.g. a poly film wrapper, is invisible to normal optical inspection devices. A method for inspecting the condition of the wrap is needed to ensure the packaging is intact and defective goods are not shipped.
C. Summary of the Invention
Applicants have developed a novel imaging process to inspect polymeric film seals and folds. Incident light is applied to the package to cause either reflected or transmitted light to reflect a pass through the poly wrap. The wrap will affect the transmitted or reflected image in a manner which can be analyzed to determine the quality of the poly film application.